This invention is implemented in the context of the IBM Continuous Speech Recognition System (ICSRS) described in the co-pending U.S. patent application Ser. No. 07/948,031, filed Sep. 21, 1992 by V.M. Stanford, et. al. entitled "Telephony Channel Simulator for Speech Recognition Application", assigned to IBM Corporation, and incorporated herein by reference.
The System is further disclosed in the co-pending U.S. patent application Ser. No. 07/947,634, filed Sep. 21, 1992 by V.M. Stanford, et. al. entitled "Instantaneous Context Switching for Speech Recognition Systems", assigned to IBM Corporation, and incorporated herein by reference.
Much of the terminology described is defined in detail therein. It is to be emphasized that only one preferred embodiment is implemented in this system, but the principles of the invention will apply to a variety of hidden Markon Modelling or HMM-based speech recognition implementations using word, or phrase, models to compete with sub-word models in the analysis of a continuous speech data stream. Also, while the method has been shown to execute using less computation with the reduced phoneme set as sub-word models described below, algorithms using larger, or smaller, phoneme sets, or other sub-word models are anticipated by this invention.